Answer:
Equation that can be used to get x is; x2 + 14x - 51 = 0
Value of x (width of the walkway) = 3 meters
Step-by-step explanation:
Since the width of the walkway is x m, then;
The length of the rectangle is (2x + 16) and
The width of the rectangle is (2x + 12). The area of the rectangle is 396.
Therefore;
(2x + 16)(2x + 12) = 396
4x2 + 24x + 32x + 192 = 396
4x2 + 56x - 204 = 0
x2 + 14x - 51 = 0
(x + 17)(x - 3) = 0
x + 17 = 0 or x - 3 = 0
x = -17 or x = 3
Discard the negative value and you are left with the width of the walkway being 3 meters wide.